This invention relates in general to molding assemblies and, in particular, to safety devices associated with separable mold components.
More specifically, but without restriction to the particular use which is shown and described, this invention relates to a split-mold lock for use with the separable components of a mold assembly having one or more parting lines. The split-mold lock of the invention is capable of automatically assuming a locked configuration to prevent separation of the mold components during lifting and manipulation, while permitting separation when the mold assembly is supported by support elements. The mold lock of the invention allows an operator to lift mold components as a unit and lift them without the fear of undesired separation. The mold lock attains automatic release of the components when returned to an operative position in association with a press.
In the art of molding, such as in the fabrication of plastic containers and the like, it is common to mold an article within a mold assembly having a suitable cavity and die design provided by separate mold sections that are moved together in a mold press. After using a specific unit for a desired number of operations, it may be necessary to replace the mold assembly in use with another unit of different design. The changeover is accomplished by lifting the prior separable mold from the press by a hook or other implement and transferring it to a storage area or other use. It is during the carrying of a mold from the press when a particularly dangerous situation is created by such handling.
In prior art designs, the closed molds are lifted by numerous techniques, such as by contact with a ring of a handle, which is mounted on one of the mold sections. Since this ring is only mounted on a single mold section, it is common for the sections of the mold to separate during lifting and create a hazard to the operator or cause potential damage to a component. As a protection against undesired separation of the components at a parting line, one known technique of locking the mold sections together employs a strap plate anchored to adjoining sections across the parting line. The attachment and removal of such a fixed safety device is inconvenient and time consuming, since it must be affixed prior to lifting. On occasion, this technique is potentially dangerous when a mold is returned to use on the press and is separated with the safety plate in place, since the screws may pop outward as projectiles. The problems in the prior art of providing protection against disjointing of mold sections during transport is aggravated in situations involving molding assemblies having several molding components and parting lines.